Heh, Oqsy getting me to post,

.
Well, without looking up the chip specs (pin out)...it might actually be an ON switch, or at least providing some sort of Vcc to the Motorola chip. Give me a few minutes, I'll go try to find a spec sheet for Motorola chip.
Edit:
Taking a closer look, may not be Vcc after all. The switch connects some external wire to the Motorola chip. I can't see the wire because it's hidden behind other wires, but it's connected to the same trace as "C4" (not at C4, but close by, no lable for it).
My time being limited today, haven't been able to find a data sheet for the controller. As that could be a big hint, though I suspect it's just an input of sorts for something, and the wire it's connected to will probably give a better indication.